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Reactive-oxygen-species are produced more often in the body when bisphenol A (BPA), an endocrine-disrupting-substance, is present. In this investigation, bio-sorbents from an aqueous solution adapted from Aloe-vera were used to survey BPA removal. Aloe-vera leaf wastes were used to create activated carbon, which was then analyzed using Fourier transform infrared (FTIR), Field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Thermogravimetric analysis (TGA), Zeta potential, and Brunauer-Emmett-Teller (BET) techniques. It was revealed that the adsorption process adheres to the Freundlich isotherm model with R2>0.96 and the pseudo-second-order kinetic model with R2>0.99 under ideal conditions (pH = 3, contact time = 45 min, concentration of BPA = 20 mg.L−1, and concentration of the adsorbent = 2 g.L−1). After five-cycle, the efficacy of removal was greater than 70%. The removal of phenolic-chemicals from industrial-effluent can be accomplished with the assistance of this adsorbent in a cost-effective and effective-approach. [ABSTRACT FROM AUTHOR]

Distributed switched large-scale systems are composed by dynamically coupled subsystems, in which interactions among subsystems vary over time according a switching signal. This paper presents a distributed robust switched model-based predictive control (DSwMPC) to control such systems. The proposed method guarantees stabilising the origin of the whole closed-loop system and ensures the constraints satisfaction in the presence of an unknown switching signal. In the distributed model-based predictive control (DMPC) used in this work, by considering the interactions among subsystems as an additive disturbance, the effect of the switch is reflected on the dynamic equation, local, and consistency constraint sets of the nominal subsystems. To compensate the effect of switching signal which creates a time-varying network topology, a robust tube-based switched model-based predictive control (RSwMPC) with switch–robust control invariant set as the target set robust to unknown mode switching is used as local controller. The scheme performance is assessed using three typical examples. The simulation results show that the input and state constraints are satisfied by the proposed DSwMPC at all times. They also validate that the closed-loop system converges to the origin. Also, a comparison of the DSwMPC with a centralised SwMPC (CSwMPC) and a decentralised SwMPC (DeSwMPC) are performed. [ABSTRACT FROM AUTHOR]

This article proposes the consensus tracking of multi‐agent systems, in the presence of Byzantine agents and loss of connection between agents and the reference signal. The main purpose of this work is to steer a multi‐agent system to the desired reference, assuming that there are some agents which send incorrect information to the other agents, and the connection between the agents and the reference signal may lose. Using graph properties alongside the weighted‐mean‐subsequence‐reduced (W‐MSR) algorithm led to a novel control method for multi‐agent systems. With the aid of model predictive control (MPC), the agents reach the desired consensus with connection loss of reference signals, misbehaving agents in the system, and constraints on the input signals. Combining MPC with the W‐MSR algorithm results in an algorithm called reference‐based‐W‐MSR (RBW‐MSR), which has made the consensus point fixed according to a predetermined reference. A theorem is illustrated to guarantee the consensus with the interruption of reference signals and agents. The effectiveness of the proposed algorithm is illustrated via simulation results. [ABSTRACT FROM AUTHOR]

In this paper, finite-time contractive stability analysis and observer-based H ∞ fault tolerant control problem is discussed for a networked single-link flexible manipulator subject to external disturbance, actuator, and sensor faults. The variable delay is considered in both sensor-to-controller and controller-to-actuator channels. In order to conserve the network resources and avoid Zeno phenomenon, the sampled-data-based event-triggered scheme is employed, which only requires the system states in discrete instants. The nonlinear unknown input observer is first designed to achieve the estimation of the system states and faults simultaneously. To reduce the conservatism of designing procedure, the Lyapunov–Krasovskii functional approach is used, which includes the information of the lower and upper bounds of variable data transmission delay. Then, sufficient delay dependent conditions are derived and an observer-based feedback control law and observer gains are computed by a set of linear matrix inequalities to realize that the augmented system is finite-time contractive stable and the states of the system remain within a specified threshold during a fixed time interval, which is smaller than the initial state bound. Furthermore, the prescribed H ∞ performance is satisfied in the presence of external disturbance. At last, simulation results are given to confirm the validity of the presented approach. [ABSTRACT FROM AUTHOR]

This study considers the designing of the H ∞ sliding mode controller for a singular Markovian jump system described by discrete-time state-space realization. The system under investigation is subject to both matched and mismatched external disturbances, and the transition probability matrix of the underlying Markov chain is considered to be partly available. A new sufficient condition is developed in terms of linear matrix inequalities to determine the mode-dependent parameter of the proposed quasi-sliding surface such that the stochastic admissibility with a prescribed H ∞ performance of the sliding mode dynamics is guaranteed. Furthermore, the sliding mode controller is designed to assure that the state trajectories of the system will be driven onto the quasi-sliding surface and remain in there afterward. Finally, two numerical examples are given to illustrate the effectiveness of the proposed design algorithms. [ABSTRACT FROM AUTHOR]